The present invention relates to a connection between a first, supporting structural member, such as a post or header, and a second, supported structural member such as a joist or rafter. The connection is made with a connector and fasteners, the use of which can be substantially hidden from view. The connector is inserted in a slotted opening in the second, structural member and attaches to a surface of the first, supporting structural member.
German Utility Model No. 90 01 067 teaches a concealed joining element made from a sheet of relatively thin material whose effective thickness is increased by providing deformations or beads in the sheet metal so that the attachment web of the connector will fit more snugly in the slotted opening of the second structural member and thus prevent looseness in the connection.
German Utility Model No. 92 05 490 also teaches a concealed joining element made from a sheet of relatively thin material, but instead of providing the attachment web with deformations and beads to increase its effective thickness, the invention crimps or folds the material of the openings over on themselves to increase the effective thickness of the attachment web of the connector.
German Patent No. DE 41 24 553, published in March of 1992, teaches a two-part, concealed joining element. Two similarly-shaped, L-shaped members are joined together so that their larger flanges overlap to form an attachment web that is inserted into the slotted opening of the second structural member, and where the smaller flanges of the L-shaped members make up the fastening flanges that attached to the supporting structural member. The flanges that make up the attachment web are provided with deformations or embossed portions to increase the effective thickness of the combined attachment web.
U.S. Pat. No. 5,062,733, granted in 1991, teaches a concealed joining element with special openings for receiving the dowels that connect the attachment web of the joining element to the second structural member.
U.S. Pat. No. 5,598,680, granted in 1997, teaches a concealed joining element with special fastening flanges that extend to both sides of the attachment web.